Not to shoot anyone down but I wouldn't label a volt mod as "simple" especially if it's your first attempt at such an experiment on your fancy $400 card, and warranty will be pretty much screwed as they'll be blatant evidence of soldering
In some situations you can lucky with the PCB, such as the case with the 6800GT where you could modify the bios to increase the core voltage with no physical modding neccesary, although GTs did have a reputation of dying after a few months with the extra voltage